Millions of pieces of mail are deposited with the postal service every day. The deposited mail is sorted, generally by zip or other code, and shipped to the proper destination. Generally, the sorting process involves placing mail with the same or related codes into tubs or trays. Thus, each tub or tray will contain mail addressed to geographically proximate locals. The tubs and trays are then placed on pallets and carts and the pallets and carts are loaded on trucks or other vehicles for shipment to their appropriate destinations.
Some parts of this process have been automated, including the sorting of mail by zip code. However, the loading of tubs and trays onto pallets and carts is generally done by hand. While hand or manual loading accomplishes the desired result, it requires postal staff to be engaged in physically demanding and tedious work. Moreover, the speed at which pallets and carts can be loaded is limited by the speed at which the human body can operate and the number of people that can economically be employed to carry out the task. With ever increasing mail demands, faster, more efficient methods of loading pallets and containers with mail tubs and trays are needed.